1. Field of the Invention
This invention relates to a workpiece positioning and securing apparatus and more particularly to apparatus for positioning and securing a pair of workpiece components to be connected together in a predetermined special relation and for moving a securing device such as a welding machine into a position relative to the first and second workpiece components for securing the members at a predetermined location.
2. Description of the Prior Art
Devices for positioning workpiece components for fastening or securing the components in a preselected manner are well known in the art. For example U.S . Pat. No. 2,787,700 illustrates and discloses a work feeding and positioning mechanism for feeding a part to two operative positions relative to a pair of welding electrodes of a welding apparatus. A carriage is reciprocated toward and away from the welding electrodes and includes a work holder for carrying a part to and accurately positioning it between the electrodes for welding of a pair of contacts thereon. The work holder is mounted on the carriage for transverse movement thereof. The length of the transverse movement of the work holder on the carriage is adjustable whereby the work holder accurately locates the part successively in two positions while the two contacts are sequentially welded thereto in a predetermined spaced relation to each other.
U.S. Pat. No. 1,714,867 discloses a welding apparatus adapted for use in the construction of sheet metal shells and particularly internally trusssed sheet metal doors. The trussed sheet metal doors include a truss structure first welded to a back plate and the truss structure is welded to a front plate. The back plate is placed on a table between rails and the trussed structure is placed on top of the back plate. The rails are adjusted and secured by bolts to permit the door to be moved between the rails. A main feed mechanism positions the door in respect to the electrodes for the first spot welding operation. A lower electrode remains fixed while an upper electrode is manually operated to move into position relative to the lower electrode for forming the spot weld operation of the welding mechanism. The operation is sequential in that the sheet metal door members are first initially moved to a position with respect to the electrodes followed by the step of clamping the back plate and trussed structure together by the movement of the upper electrode in respect to the lower electrode. With the members in a predetermined position a row of spot welds are made along the length of the door at a preselected distance from each other. After one row of spot welds are made the door is moved to a position for making a second row of spot welds.
U.S. Pat. No. 1,464,207 discloses an assembling and welding jig for assembling and electrically welding the parts of automobile bodies. A positioning member is operable to position a cowl panel and hold it correctly positioned with reference to the framework of the jig and body frame members to which it is to be welded. The positioning member is arranged to be swung into and out of an operative position to permit the removal of the body frame and cowl from the welding jig and the insertion of a body frame and cowl panel to be connected together.
While it has been suggested by the prior art devices to move a pair of components into a preselected position for fastening together as by welding or the like, the prior art devices require the components to be moved by a carrier type mechanism into a predetermined position relative to a welding machine that remains fixed relative to the components. Once the components are located in the predetermined position the electrodes of the welding machine are moved into an operative position with respect to the components for welding. This arrangement is cumbersome and is not readily adaptable to welding and other fastening operations where movement of the welding machine from place to place to carry out the welding operation is required.
Portable spot welders are known such as illustrated and described in U.S. Pat. Nos. 2,441,438 and 2,535,946. The spot welders disclosed in these patents are designed to be manually moved from place to place to perform spot welding operations. The portable spot welder includes a pair of electrodes or tongs in which welding tips are provided at the end of the tongs and are adapted to be pressed toward each other against the components of a workpiece disposed therebetween. A lower tong is fixed, and an upper tong is pivotally connected to a cap of the welder to be moved by a toggle mechanism into contact with one surface of the workpiece.
With the above described portable spot welding apparatus the workpiece components must be initially positioned in a predetermined relationship to each other for spot welding. Generally this is done manually and with the aid of clamps and other devices to secure the components together before they can be welded. Not only is this operation time consuming but requires a number of operating personnel. Therefore there is need for a positioning apparatus in combination with fastening devices, such as spot welders and the like, that are readily movable from place to place and provide for precise positioning of the components relative to the welding or securing machine in an efficient manner that reduces the time for the spot weld to be made and the number of operating personnel to carry out the spot welding operation.